In motor assembly situations, it is typically necessary to assemble a motor shaft within a motor housing. Additionally, it is often necessary to affix a component to the motor shaft after the motor shaft and the motor housing are assembled. In many applications, it is also necessary for a motor to drive an apparatus located a significant distance from the motor.
One method of assembling a motor shaft in a motor housing includes the step of installing a snap ring into a groove in the motor shaft. The snap ring serves as a retainer for a bearing that is pressed onto the motor shaft. The motor shaft and associated components are installed into the motor housing with one end of the shaft protruding from the housing. A barrel spacer is then fitted onto the shaft next to the bearing and protrudes from the motor housing. A first washer is slid onto the protruding end of the shaft and abuts the barrel spacer. In certain applications a component, such as an impeller, may also be slid onto the protruding end of the shaft into abutment with the first washer. A second washer is placed onto the motor shaft to sandwich the component between two washers. A hex nut is then threaded onto the end of the protruding shaft to hold all components on the shaft together in an axial direction against the snap ring. The threaded nut serves to apply pressure to the washers, which in turn hold the impeller to insure that the impeller rotates as the motor shaft rotates.
For applications where the motor is used to drive an apparatus located a significant distance from the motor, a shaft extension is typically threaded onto the end of the motor shaft. The shaft extension is coupled to the apparatus in any suitable manner.
The previously described method has disadvantages. When a motor having a long shaft is operated, torsional forces create shaft whip and wobble that create noise and vibration during motor operation, this problem is compounded when a threaded shaft extension is used. The installation of the threaded shaft extension onto the motor shaft often results in misalignment between the shaft extension and the motor shaft.